YOKOGAWA WT1800 User Manual page 135

Data update interval
Measurement period
Unintended zero crossing caused by pulse noise
Setting the Synchronization Period When Measuring a Three-
Phase Device
If a three-phase device is measured with input elements 1 and 2 using a three-phase, three-wire
system, set the synchronization source of input elements 1 and 2 to the same signal. For example, set
the synchronization source of input elements 1 and 2 to U1 or I1. The measurement periods of input
elements 1 and 2 will match, and it will be possible to measure the Σ voltage, Σ current, and Σ power
of a three-phase device more accurately.
Likewise, if a three-phase device is measured with input elements 1, 2, and 3 using a three-phase,
four-wire system, set the synchronization source of input elements 1, 2, and 3 to the same signal.
To facilitate this sort of configuration, the synchronization source setting on the WT1800 is linked to
the Σ wiring unit of the wiring system (when independent input element configuration is turned off).
If independent input element configuration is turned on, the synchronization source of each input
element in the Σ wiring unit can be set independently.
Synchronization
source
Input signal U1
Input signal U2
Input signal U3
Synchronization Source Setup Example
IM WT1801-03EN
When the
synchronization source
setting is turned off
Data update interval
Measurement period
Input element 1
U1 (or I1)
Input element 2
Input element 3
Appendix 5 Setting the Measurement Period
Data update interval
Measurement period
1
2
3
4
5
6
App
Index
App-29